Vehicle sobriety interlock device

ABSTRACT

An interlock device for measuring the sobriety of a potential vehicle operator is coupled to the starting mechanism of the vehicle. The interlock device includes a microprocessor controlled handset and base unit. The base unit encloses relays to preclude the starting mechanism from engaging if a predetermined acceptable threshold level of blood alcohol content has been exceeded. The relays receive a signal, through the base unit microprocessor, from the handset microprocessor which has calculated the blood alcohol content of a breath sample introduced into the handset by the vehicle operator. A breath sampling housing is enclosed within the handset in axial alignment with an intake port of the handset. A water filter and valve are positioned upstream from an electrochemical fuel cell. The fuel cell is coupled to the microprocessor. A pressure transducer measures the pressure of the breath sample. The handset microprocessor calculates a pressure offset through an algorithmic equation and applies the offset to the variable reading across the fuel cell to provide a normalized blood alcohol content measurement.

PRIOR APPLICATION

This application bases priority on International Application No.PCT/US03/34650, filed Oct. 31, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an improved sobriety interlock device. Moreparticularly, it relates to a sobriety interlock device for use invehicles and motorized machinery apparatus, the device incorporatinganti-circumvention features and an improved sampling system to providefor more accurate measurements of the blood alcohol content of anunsupervised operator of a vehicle or motorized machinery apparatus.

2. Background of the Prior Art

Breathalyzer testing and sobriety interlock devices for use in vehicles(automobiles) and motorized machinery for industry are well known in theprior art. These types of devices work on a principle that the breath ofa person who has consumed alcoholic beverages can be sampled todetermine a corresponding blood alcohol content (blood to alcohol ratio)of that person. Using known levels of blood alcohol content, it can thenbe determined whether someone has too much alcohol in their system whichwould effect their ability to operate machinery or a vehicle. Forinstance, many states use a level of 0.08 as a percentage of bloodalcohol content which acts as a presumption that a person is intoxicatedand unable to drive a vehicle.

Early advancements in breathalyzer testing devices can be seen in U.S.Pat. No. 3,764,270 to Collier et al. wherein an alcohol concentrationmeasuring apparatus is disclosed. In this reference it is noted that theoperation of vehicles and machinery by persons intoxicated by alcohol isa major health problem in many places in the world and especially in theUnited States. The device of this prior art reference teaches that deeplung breaths are required to measure an accurate blood alcohol contentfrom a gas sample or more accurately, the breath. Accordingly,improvements over then existing prior art devices are made in thisCollier et al. reference that address measuring the alcoholconcentration by ensuring a continuous and uninterrupted flow of gasfrom a subject using such device. However, it is not contemplated thatthis device could then be interfaced with the starting mechanism of avehicle in the event that a predetermined threshold of the measuredblood alcohol content is exceeded. This feature is clearly needed.

Subsequent devices seen in the prior art have addressed the need for asobriety measuring device to be interfaced with a vehicle's startingmechanism—a so called “interlock” device. For instance, U.S. Pat. No.3,831,707 to Takeuchi describes an early interlock device which takes aseries of measurements to determine the temperature, humidity andalcohol concentration of the vehicle operator's breath. Thesemeasurements can be taken after the ignition switch of the vehicle(i.e., automobile) is engaged, thereby permitting the operator of thevehicle to warm up the car, by blowing into a sampling apparatus.Predetermined permitted ranges are set within the device for these threemeasurements. If the three readings fall within the permitted ranges(all three conditions pass), the automobile's transmission can beengaged and the car can be operated. If not (the test fails), thetransmission of the automobile will not engage thereby preventingoperation of the vehicle based upon an assumption that the operator isintoxicated and therefore lacking the required mental faculties tooperate the vehicle. The temperature and humidity readings are used tosense that the air subjected to the sampling apparatus is in fact ahuman breath. Accordingly, these readings assist somewhat in theanti-circumvention of the interlock device. However, temperature andhumidity can fluctuate substantially depending on the climate in whichthe vehicle is located and thereby effect the test being taken.Accordingly, there is a great need to improve upon temperature andhumidity sensing systems that work in coincidence with the alcoholsensors to provide more accurate measurements for interlock devices.Further, other more sophisticated anti-circumvention features are neededin interlock devices to thwart attempts by users to fool the devicethereby permitting their vehicle to be operated when it clearly shouldnot.

Other advancements in the prior art for sobriety interlock devices havebeen made that do not directly address temperature and humidity sensing.In particular, advancements in measuring a continuous and uninterruptedflow of breath for the sampling device can be seen in U.S. Pat. No.4,093,945 to Collier at al. which again addresses the need for samplinga deep lung breath since it is known that, absent some flow ratemeasurement equalization algorithm within an interfacing softwareprogram, deep lung breath samples are more apt to provide an accuratemeasurement of the blood alcohol content of the test taker than a shortand shallow breath. The device of this prior art reference works toexclude breath samples that are not deep lung samples thereby requiringthe individual taking the test to repeat the test until the deviceindicates that the breath sample was a deep lung breath sample.Unfortunately, this device can be difficult to use since not allindividuals are capable of providing a deep lung sample needed to takethe measurement. Improvements for measuring the flow rate of the breathsamples are certainly needed. Such improvements should utilize aninterfacing software program that can operate to equalize the breathsamples through algorithmic offset calculations regardless of how deepor how shallow they are to provide the most accurate measurementpossible.

Still other advancements in prior art interlock devices address operatoridentity. Since most states in the U.S. have already mandated the use ofinterlock devices for convicted DUI (driving under the influence ofalcohol) offenders, operator identity of an unsupervised test can becritical. It is quite reasonable to assume that an inebriated vehicleoperator may simply ask a sober person to take the test for them so thatthe vehicle starting mechanism can be engaged upon receiving a “pass”result since the test would be otherwise unsupervised. Although this actin itself is probably punishable by a fine or even incarceration in moststates, it most likely has occurred and will continue to occur in thefuture. Accordingly, the inventions seen in U.S. Pat. No. 4,738,333 toCollier et al. and U.S. Pat. No. 4,809,810 to Elfman et al. and U.S.Published Application No. U.S. 2002/0084130 to Der Ghazarian et al. weredeveloped to address operator identity so that the person mandated (by aCourt for example) to take the sobriety test before the vehicle can beoperated is the individual actually taking the test. It is important tonote however, that these interlock devices are known to be morecomplicated and thereby require more maintenance/calibration, moreexpense and more sophisticated circuitry. Although there is a great needto ensure that the proper person is taking the sobriety test, suchcomplicated and expensive devices may be overlooked and not employed dueto their over-sophistication. There is clearly a need to keep sobrietyinterlock devices simple in their design but accurate in theirmeasurement. Other, more simpler anti-circumvention technology should beused to ensure that drunk drivers are kept off the road. Development ofa secure anti-circumvention interlock device that does not involvecomplex personal identity scans is clearly needed.

Most modern interlock devices include a few common elements: a powersupply, a fuel cell (alcohol sensor), a sampling system (a breath intakechannel leading to the fuel cell), a microprocessor to analyze theresults of the test taken by the fuel cell and an output (a relayconnected in series with the starter of the vehicle). In breath analyzerdevices (those which are not used as interlock devices), output relaysare not necessary since such devices are not intended to prevent theoperation of a vehicle but merely used to give a blood alcohol contentmeasurement. However, other common elements can be found, even thoughtheir uses may vary. Indicative of the use of a microprocessor in abreath analyzer device (but not that necessarily of an interlockdevice), as shown in U.S. Pat. No. 4,749,553 to Lopez et al., amicroprocessor is employed to calculate the blood alcohol content byrunning an algorithm contained within the memory of the microprocessorusing a plurality of signals-generated by taking a sample breath,including: an alcohol signal, a distance signal to compensate fordiffusion of the exhaled breath, a pressure signal and a temperaturesignal. These types of signals are known as environmental signals andare helpful in securing a more accurate blood alcohol contentmeasurement based upon ambient environmental conditions which may effectthe measurement and give a false positive (a test fail). However, thisdevice lacks important anti-circumvention features which are needed foruse in interlock devices for preventing false measurements intended to“fool” the analyzing device. Anti-circumvention features are criticallyneeded in interlocking devices since almost all measurements are takenin an unsupervised location. Further, the actions of DUI offenders undera court order to have the interlocking devices installed in theirautomobile will be under review. It will be imperative for thesupervising agency (i.e., Probation Officer) to determine whether theinterlocking devices have been circumvented, tampered with or not usedwhen instructed (i.e., “rolling repeat tests”). Accordingly, use of datalogs should be employed as a deterrent to the person mandated to use thedevice as well as for use in monitoring the life and proper function ofthe interlocking device.

One example of device circumvention includes using a gas source otherthan a current human breath, say from a balloon, to fool the device intothinking that an actual test is being made. One method to prevent suchcircumvention can be seen in the device of U.S. Pat. No. 4,902,628 toBlair. This device requires a positive and negative breath sample(blowing then sucking) to provide a measurement of the breath beingtested and hence the blood alcohol content of such person. This deviceis first blown into by the person being tested, then the person isrequired to apply a suction after a short time lapse. Accordingly, afirst and second signal are generated. If both signals are notrecognized by a control means, a measurement will not be provided, thetest will fail and the vehicle will not be permitted to start. Thishelps to ensure that an improper gas is not used to take a test on adevice that merely requires the person to blow into such device.However, this type of device still could improved by employing enhancedanti-circumvention features.

In order that an accurate reading of the blood alcohol content ismeasured, it is important that the fuel cell not be exposed to too muchpressure from a strong breath sample or too little pressure from ashallow or weak breath sample. Some prior art devices have attempted toaddress this problem. In those devices that utilize a valve upstreamfrom the fuel cell, some have used a pressure transducer to control theopening and closing of the valve. This can be seen in U.S. PublishedApplication No. U.S. 2003/0176803 to Gollar. In such device, thepressure transducer measures the pressure of the gas sample (humanbreath) and controls the opening of the valve in response to themeasured pressure—a so called “constant volume” sampling system. Thisdevice integrates a pressure feedback signal to obtain a volumericequivalent. The valve time opening varies from sample to sample basedupon the measured pressure. In other words, the opening of the valve isdirectly dependent on the measurement taken by the pressure transducer.

A similar prior art device can be seen in U.S. Pat. No. 6,167,746 toGammenthaler which utilizes a normally closed valve. The valve opens tocontrol the volume of the breath sample by measuring the pressure of thebreath flow through the device and, in response to the measuredpressure, electronically controls the opening of the valve and diverts aportion of the breath flow into the fuel cell. A valve controller limitsthe duration of time that the valve is open based upon the measuredpressure of the breath flow. In other words, the valve is dependent onthe valve controller which in turn is dependent on the pressuremeasuring device.

An improved device is clearly needed wherein the valve worksindependently of the pressure transducer and permits a breath sample topass there through without regard to the amount of pressure in thesample. The improved device should instead compensate for varyingpressures through an algorithmic calculation and not through electronicvalve controllers and pressure measuring devices.

It is clearly seen that an improved interlock device is needed which canprovide for a more accurate blood alcohol content measurement all thewhile having the necessary anti-circumvention features that ensuresindividuals will use the device as intended. The device should be lesscomplicated then those devices seen in the prior art such that greaterease of operation can still be achieved. Improved accuracy should beenjoyed through a microprocessor controlled valve working independentlyfrom a pressure sensitive component. The improved device should permitthe logging of data relative to the operation of the device so that asupervising agency can review the log to see if circumvention ortampering of the device has occurred and to otherwise see that thedevice is working properly. Other features that monitor the status ofthe vehicle's movement would also help to ensure that circumvention isnot attempted through idling of the vehicle while the person consumesalcohol away from the car that has already been started. Further,rolling repeat tests during operation of the automobile would help toensure that alcohol is not being consumed by the driver during operationof the vehicle after it has been started (i.e., driving down the highwayand consuming alcohol). Other improvements are also needed to ensurethat the most accurate measurement is always provided. For instance,through the use of water filtering, moisture can be virtually eliminatedfrom the breath vapor thereby avoiding moisture saturation of the fuelcell (the alcohol sensor). Improvements in temperature monitoring andtemperature control of the device should also be practiced to ensurethat the device works properly in cold weather climates.

SUMMARY OF THE INVENTION

We have invented an improved vehicle sobriety interlocking device thatovercomes all of the short comings seen in the prior art. Our deviceutilizes a base unit and handset in communication with one another andwhich are installed within close proximity of the driver's seat of avehicle or motorized machinery. The base unit includes at least onerelay which is electrically wired in series with the starter of thevehicle. The handset is microprocessor controlled and is used as thebreath testing device and analyzer. Both the base unit and handset canbe powered from the 12V DC battery of the vehicle. The base unit alsocontains a microprocessor which interfaces with the handsetmicroprocessor through a high speed serial data interface.

Our device includes a handset having a front and back portion enclosinga printed circuit board. Included on the printed circuit board is amicroprocessor which interprets a breath sample taken from a samplingsystem within the handset and thereafter sends a high speed serial datasignal to the base unit microprocessor for controlling a set of relays.If the result of the sobriety test is that a predetermined threshold(for example 0.03%) has not been exceeded, then the appropriate signalis sent so that the relays change state thereby permitting the starterof the vehicle to be engaged and the vehicle to be operated. If theresult of the test is that the predetermined threshold has beenexceeded, then an appropriate signal is sent such that the relays do notchange state whereby the starter can not be engaged and hence thevehicle can not be operated (precludes ignition). An LED display coupledto the microprocessor instructs the user when to blow and whether thetest taker passed or failed the sobriety test. Other messages can bedisplayed, including, but not limited to, the number of days remainingbefore the next servicing, before the next monitoring (i.e., download)or before the next calibration.

Enclosed within the handset is a sampling system housing incommunication with a breath intake port forming a breath channel. Thesampling system housing includes a body portion, a fuel cell, a solenoidvalve, a water filter, a housing heater, a temperature sensor and acapillary tube attached at a first end to the water filter and at asecond end to a pressure transducer mounted on the printed circuitboard. The breath channel has a temperature sensor mounted through thehousing body for determining whether the gas sample is that of a currenthuman breath. The water filter reduces the amount of moisture that isexposed to the fuel cell by passing alcohol vapors while precludingwater in the gas sample from reaching the fuel cell. The solenoid valveis positioned upstream from the fuel cell and remains open for a finiteperiod of time to pass the gas sample to the fuel cell. The handsetmicroprocessor controls the opening and closing of the solenoid valve.The solenoid valve is open for a constant and finite, albeit short,period of time. The pressure transducer is coupled to the microprocessorbut does not control the opening and closing of the solenoid valve butinstead works to normalize the breath samples that are introduced to thebreath channel through an algorithmic calculation.

A proprietary software program embedded upon the microprocessorinterprets the pressure levels of the breath samples and equalizes themeasurements made across the fuel cell by calculating an offset throughthe mathematical algorithm based upon predetermined standard breathsamples. Accordingly, a standard alcohol response equation is programmedin the microprocessor. During calibration of the interlock device, thehandset determines appropriate valve opening time required to achieve aparticular sample based upon predetermined pressure (an example of aparticular sample is 0.03% blood alcohol content). Once this value isdetermined, the valve opening time is fixed for each interlock deviceuntil the next time the handset is calibrated.

The pressure measurements that are used to normalize the breath samplesare taken by the pressure transducer at some finite time after thesolenoid valve first receives flow through the valve. The calculatedoffset ensures that higher flow rates due to higher pressure readings donot give false positive readings (the reverse also being true; ensuresthat lower flow rates due to lower pressure readings do not give offfalse negative readings). These components provide a more accuratereading for the novel interlock device of the present invention and alsowork as an anti-circumvention feature whereby the user can not fool thedevice by introducing a shallow low pressure breath sample.

A pair of accelerometers are mounted on the circuit board of the baseunit to constantly measure movement of the vehicle in either an X or Yaxis. These measurements are used to determine whether the vehicle ismoving (i.e., accelerating) or turning. Accordingly, the accelerometercan be used as an anti-circumvention feature for the interlock device ofthe present invention. Results of these measurements are recorded in adata log which can be downloaded by a supervising agency. The data logwill show whether the car was idling for any questionable amount oftime. This acts as a deterrent against court mandated users fromstarting their vehicle when they are completely sober, driving to anestablishment serving alcoholic beverages, leaving their vehicle running(idling) while they consume alcohol and then return to their vehicle todrive away drunk. Also, the accelerometers act as a bypass detector todetermine whether the vehicle was moving at a time when no test by theinterlock device was first initiated (vehicle was started without aninterlock device test being performed).

Other anti-circumvention features include rolling repeat tests wherebythe user has to blow into the mouthpiece of the handset while driving toensure that alcohol has not been consumed since the vehicle was started.Although the interlock device of the present invention will not disablea running vehicle in the event of a failed test, the data log willrecord such event and expose the violation to the supervising agency atthe time of download of the data log. Further, relays can switch onlights and blow the horn to attract attention to the violator. A miniUSB B port is in communication with the handset microprocessor and actsas a point of download for the data log as well as an upload point forsupervisor preferences and settings. Downloads and uploads can also beeffected through wireless transmission. A second proprietary softwareprogram can be used on a laptop or PC to set preferences and settingsfor the interlock device, to perform calibrations and to interpret thedata log.

As used herein, vehicles and motorized machinery apparatus include, butare not limited to, automobiles, trucks, ships motorcycles, boats,planes, trains, tractors, mowers and other industrial and constructionvehicles which include a motor and an ignition system.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be best understood by those having ordinary skill inthe art by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings in which:

FIG. 1 is a top plan view of a handset used with an interlock device ofthe present invention;

FIG. 2 is a front elevational view of the interlock device handset ofthe present invention depicting an LED display employed within thedevice handset;

FIG. 3 is a left side elevational view of the interlock device handsetof the present invention;

FIG. 4 is an exploded view of the interlock device handset of thepresent invention;

FIG. 5 is a front elevational view of a printed circuit board having abreath sampling housing mounted on a top portion thereof employed withinthe interlock device handset of the present invention;

FIG. 6 is a rear elevational view of the printed circuit board havingthe breath sampling housing mounted on the top portion thereof employedwithin the interlock device handset of the present invention;

FIG. 7 is an exploded view of the breath sampling housing;

FIG. 8 is a left side elevational view of the breath sampling housing;

FIG. 9 is a cross-sectional view of the breath sampling housing alonglines 9—9 of FIG. 8;

FIG. 10 is a right side elevational view of the breath sampling housing;

FIG. 11 is a is a cross sectional view of the breath sampling housingalong lines 11—11 of FIG. 10;

FIG. 12 is a left side elevational view, partially in section, of theinterlock device handset of the present invention;

FIG. 13 is a perspective view of a base unit employed with the interlockdevice of the present invention;

FIG. 14 is an exploded view of the base unit employed with the interlockdevice of the present invention;

FIG. 15 is a flow diagram illustrating the manner in which air flowsthrough the handset and the breath sampling housing and how certainmeasuring components of the interlock device of the present inventioninteract;

FIG. 16 is a first graph illustrating a raw alcohol measurement (testresult) versus breath flow (pressure) through the handset; and

FIG. 17 is a second graph illustrating a pressure correction factorcurve (offset) correlating to a raw pressure value.

DETAILED DESCRIPTION OF THE INVENTION

Throughout the following detailed description, the same referencenumerals refer to the same elements in all figures.

Referring to FIG. 2, a handset 10 of an interlock device of the presentinvention is shown. FIG. 2 illustrates a front view of handset 10whereby a display screen 12 is clearly seen. Display screen 12 is an LEDdisplay screen (see FIG. 5) coupled to a printed circuit board (to bediscussed hereinafter) enclosed within handset 10 which provides for aplurality of messages to be displayed thereon, including, but notlimited to, “Warm Up”, “Blow Now”, “Fail” and “Pass”. LED display screen12 is covered by a tinted translucent cover 14 so that the messages ondisplay screen 12 are visible but all other components mounted on thecircuit board are not visible. As shown in FIG. 2, handset 10 has aconical shape thereby permitting handset 10 to be easily gripped by aperson utilizing the interlock device.

Referring now to FIG. 1, it is shown from a top plan view that handset10 includes a “power-on” button 16 that is first engaged to operate theinterlock device of the present invention. Button 16 is located on a topportion 20 of handset 10. When depressed, button 16 sends a signal to amicroprocessor which “wakes-up” handset 10 and the interlock device. Theinterlock device of the present invention can be programmed to “timeout” after a pre-determined amount of time has elapsed therebyeliminating the need for the interlock device to be powered down aftereach use. The interlock device essentially enters a sleep mode and waitsfor its next instruction to operate. However, in the alternative, theinterlock device can be programmed so that it can be powered down bydepressing button 16 again or simply shut off when the power source ofthe interlock device and handset 10 is shut down (i.e., power to anautomobile in which the interlock device of the present invention isconnected is shut off). Handset 10 also includes a “power on” indicatorLED (not shown) positioned underneath a small cover 18 positionedjuxtaposed button 16 on handset top portion 20. The indicator LED willilluminate a color, such as green, to indicate that power is beingreceived by handset 10.

As shown in FIG. 4, handset 10 includes a front and back housing member,22 and 24 respectively, which are used to enclose a printed circuitboard (PCB) 25 within handset 10. PCB 25 contains various electricalcomponents used for analyzing a breath sample of which will be discussedin further detail hereinafter. The two housing members 22 and 24 areattached by a plurality of screws entering back housing member 24 andinserting into front housing member 22. The “power-on” indicator LED,positioned underneath cover 18, and push button 16, as seen in FIG. 1,communicate with PCB 25 through ribbon connector 17.

With continuing reference to FIG. 4, handset 10 also includes amouthpiece 26 used to place between the lips of a person utilizing theinterlock device of the present invention.

Mouthpiece 26 axially aligns with a breath intake channel 28 which isformed through handset top portion 20 (see FIG. 12). In the preferredembodiment, mouthpiece 26 is secured by friction in handset top portion20 so that it can be easily removed and replaced when necessary by asmall amount of force but is retained if handset 10 is moved around. Asshown in FIGS. 1, 3 and 4, a small annular mounting peg 15 is disposedalong handset back housing member 24 for hanging handset 10 on areciprocal clip (not shown) within a vehicle.

As shown in both FIGS. 3 and 4, handset top portion 20 projectsoutwardly. This permits a breath sampling housing 30 to be positionedwithin handset top portion 20 as illustrated in FIG. 4. Breath samplinghousing 30 contains components used to sample the alcohol content of abreath sample blown into mouthpiece 26. Breath sampling housing 30contains a breath sampling channel 32 (see FIG. 9) which axially alignswith mouthpiece 26 and is positioned intermediate an entrance port 34and an exhaust port 36 of handset breath intake channel 28 (see FIG.12).

With continuing reference to FIG. 12, it can be seen how a gas sampleenters handset breath intake channel entrance port 34, permits a portionof said gas sample to enter the breath sampling channel 32 of breathsampling housing 30, thereafter expelling all remaining portions of saidgas sample out through handset breath intake channel exhaust port 36.For the purposes herein, and for the preferred embodiment of the presentinvention, gas sample means a human breath possibly containing a levelof alcohol vapors within the breath.

As shown in FIG. 6, breath sampling housing 30 mounts on a top portion38 of PCB 25. Power to all components of breath sampling housing 30 issupplied via a first connector 40 mounted on a back side 48 of PCB 25.In the preferred embodiment, first connector 40 is a removable jumper,although first connector could be a soldered contact. PCB 25 receivesits supply of power via a second connector 42 along a bottom portion 44of PCB 25 which connects to a power source (i.e., battery—not shown) ofan automobile or vehicle in which the interlock device is installed. Inthe preferred embodiment, second connector 42 is a soldered contact,although second connector could be constructed as a removable jumper.PCB 25 also includes a pressure transducer 46 mounted on PCB 25 backside 48. Pressure transducer 46 has a capillary tube 52 connectedthereto (see FIG. 6) which feeds to breath sampling housing 30 (see FIG.5). As shown in FIG. 15, capillary tube 52 directs a small portion ofthe gas sample entering breath sampling housing to pressure transducer46 to determine a pressure value of said gas sample. As will bediscussed in further detail hereinafter, the measured pressure value ofthe gas sample is used to calculate an offset, through an algorithmiccalculation, which in turn is used to provide compensation such that anaccurate measurement of the alcohol content of the gas sample can beprovided.

With reference to FIG. 5, PCB 25 also includes a speaker 162 and abattery 164, both coupled to PCB 25 along front side 50. Speaker 162provides audio signaling for power-up and power-down procedures, anindicator for test results, an indicator for circumvention warnings andas an indicator that a rolling repeat test may be required. Battery 164supports a microprocessor of handset 10 (to be discussed in furtherdetail hereinafter) and a clock (not shown) for handset 10, both locatedon PCB 25.

Referring now to FIG. 7, an exploded view of breath sampling housing 30is shown illustrating the components used therein. Breath samplinghousing 30 includes a body portion 54 having a first channel 56 (seealso FIG. 9) formed there through. Body portion 54 is rectangular-shapedand includes a front end 58 and a top side 60 which has a cut-awayportion 62 which seats a fuel cell 64. In the preferred embodiment, fuelcell 64 is a dry electrochemical fuel cell which operates by producingan electrical signal in response to a chemical reaction across the cell(the difference in the chemical reaction). Fuel cell 64 is employed asan alcohol specific fuel cell. A dry electrochemical fuel cell ispreferred over other fuel cells, such as thermo-based cells, althoughnothing herein limits the use of other known fuel cells that are capableof measuring the presence of alcohol.

With continuing reference to FIG. 7, along a back wall 66 of cut-awayportion 62, is a second channel 68 formed in body portion 54 whichcommunicates with a passageway 70 and an entrance port 74 of fuel cell64. Passageway 70 also seats a water filter 72. On an opposed side 76 offuel cell 64 from that of fuel cell entrance port 74 is an exhaust port78 and a pair of electrical contacts 80 which bundle together andcommunicate with PCB 25 through first connector 40. Of the twoelectrical contacts 80 of fuel cell 64, one provides power to fuel cell64 while the other provides a pathway to send an electrical signal toPCB 25. Water filter 72 sits within passageway 70 and is held down by agasket 82 which in turn is held down by a cover 84. Cover 84 attaches tobody portion top side 60 by screws and also works to enclose and retainfuel cell 64 seated within cut-away portion 62. Cover 84 has a smallaperture 86 formed along a right side wall 88 for receiving a distal end90 of capillary tube 52. A proximal end 92 of capillary tube 52 isattached to pressure transducer 46 at an entrance port 94 thereon (seeFIG. 6). Aperture 86 communicates with passageway 70 for permitting asmall portion of the gas sample to reach pressure transducer 46 throughcapillary tube 52. Water filter 72 is constructed from a cork-like orsponge-like material and works to eliminate water from the gas samplewhile permitting alcohol vapors to pass through to fuel cell 64. Theelimination or reduction of water from the gas sample ensures that fuelcell 64 is not exposed to excessive moisture which can lead to cellsaturation which in turn can lead to faulty readings and cell failure.

As shown in FIG. 7, breath sampling housing also contains a solenoidvalve 98 having a mounting head 100 and a valve portion 102 in airpassageway communication. Solenoid valve 98 is a normally open valve.Mounting head 100 has an outwardly extending peg (not shown) on an innersurface for inserting within a peg receiving aperture 104 formed in aright side wall 106 of breath sampling housing body portion 54. Twoscrew bores 118 are also formed in breath sampling housing body portionright side wall 106 for receiving a pair of screws and retainingsolenoid valve 98 up against body portion 54. Also formed through breathsampling housing body portion right side wall 106, are an entrancechannel 108 and an exhaust channel 110 for solenoid valve 98 whichaxially align with reciprocal entrance and exhaust ports (not shown)formed through the inner surface of solenoid valve mounting head 100which then communicates with valve portion 102. Entrance channel 108leads from passageway 70 behind water filter 72, while exhaust channel110 leads to fuel cell entrance port 74 (see FIG. 9). Solenoid valve 98also contains a pair of electrical contacts 112, a first for providingpower to solenoid valve 98 and a second for receiving an electricalsignal which forces the valve to remain open and then to close for afinite time as instructed by a microprocessor (to be discussed infurther detail hereinafter). As stated above, solenoid valve 98 isnormally open. This acts as a “fail-safe” feature in case the valvefails. It is not desirable for the interlock device of the presentinvention to a give a false negative reading, or a “Pass” result, if infact the blood alcohol content of the test taker has exceeded thepredetermined threshold. If the valve is closed and has failed, then thetest result may be a “Pass” when in fact the test taker is actuallyintoxicated, or has at least exceeded the threshold setting for theparticular interlock device, due to the fact that fuel cell 64 would notsee any alcohol vapors pass across the cell. A false negative may thenpermit the vehicle to be operated by an intoxicated driver. In analternate embodiment, the interlock device of the present inventionincludes a valve open/close position sensor to indicate if the valve isnot in its correct position. In such alternate embodiment, the interlockdevice would be programmed such that a test could not be administered ifthe valve is in the wrong position. In the preferred embodiment,solenoid valve 98 is closed during the initialization process(“Warm-Up”), but then returns to a normally open state.

With continuing reference to FIG. 7, a temperature sensor bore 114 isalso formed through breath sampling housing body portion right side wall106 directly below valve portion 102 of solenoid valve 98. Temperaturesensor bore 114 is in communication with breath sampling channel 32. Abreath temperature sensor 116, such as a thermistor, is inserted withinbore 114 and is used to measure the temperature of the gas sampleentering breath sampling channel 32 (see FIG. 5), thereby ensuring thatthe gas sample is an actual human breath from that moment in time andnot some other gas used in an attempt to circumvent the interlockdevice. Breath temperature sensor 116 also has a pair of electricalcontacts 120 for providing power to sensor 116 and for providing apathway for a signal generated in response to a temperature measurementmade by sensor 116. The two electrical contacts 120 are bundled togetherand couple to PCB 25 at first connector 40.

With further reference to FIG. 7, breath sampling housing 30 alsoincludes a housing temperature sensor 122 and a housing heater 124.Housing temperature sensor 122 mounts along a left side wall 126 of bodyportion 54 while housing heater 124 mounts along a bottom side 128 ofbody portion. In the preferred embodiment, housing temperature sensor122 is also a thermistor and housing heater 124 is a strip of heatingtape. A strip of tape (not shown) can be wrapped around body portion topand bottom sides, 60 and 128, and left side wall 126 to enclose andretain housing temperature sensor 122 and housing heater 124. Housingtemperature sensor 122 also has a pair of electrical contacts 130 forproviding power thereto and a pathway for an electrical signal inresponse to a temperature measurement made by temperature housing sensor122. Housing heater 124 has a pair of electrical leads 132 for providingpower thereto. Both the pair of contacts and the pair of leads, 130 and132 respectively, are bundled together and connect to PCB 25 at firstconnector 40. Housing temperature sensor 122 is used to monitor thecurrent temperature of breath sampling housing 30 while housing heater124 is used to warm up breath sampling housing 30 and to hold thetemperature of housing 30 slightly above human body temperature andthereby avoid the development of condensation.

Referring to FIG. 15, the manner in which a gas sample enters breathsampling housing 30 and is subsequently measured is illustrated. Asshown, the interlock device of the present invention includes amicroprocessor 134 (mounted on PCB 25 within handset 10). Microprocessor134 is coupled to LED display screen 12. Those components enclosedwithin breath sampling housing 30 are shown to be within the dottedlines represented on FIG. 15, while those components attached to theouter walls of breath sampling housing are shown to be positionedjuxtaposed the same dotted lines. As shown, a gas sample from a humanbreath enters breath sampling channel 32 of breath sampling housing 30from breath intake channel entrance port 34. A portion of the gas sampleenters passageway 70 and is filtered by water filter 72. A portion ofthat gas sample is directed away from passageway 70 through aperture 86,into capillary 52 and into pressure transducer 46 through pressuretransducer entrance port 94 whereby a pressure reading is measured. Theremaining water filtered gas sample is expelled from passageway 70through entrance channel 108 and into solenoid valve 98. If the valve isopen, the gas sample is permitted to pass through exhaust channel 110and into fuel cell 64 at fuel cell entrance port 74. Any remainingun-needed gas sample is then expelled through fuel cell exhaust port 78.

With continuing reference to FIG. 15, it is shown that solenoid valve98, fuel cell 64 and pressure transducer 46 are all in communicationwith microprocessor 134. Microprocessor 134 first initiates a warm-upprocedure before any test is taken to stabilize handset 10. Not untilLED display screen 12 says “Blow Now” (or some other like instruction),can a test be taken. At such time, a person blows into mouthpiece 26(see FIG. 3). Microprocessor instructs solenoid valve 98 to remain openfor a finite period of time, for example, between 100 and 700 mS inresponse to detecting a minimal pressure measurement. This range allowsfor the accommodation of variable conditions. Fuel cell 64 measures thealcohol content of that gas sample and sends this measured reading tomicroprocessor 134. Some finite amount of time after solenoid valve 98opens, microprocessor 134 takes a series of pressure measurements frompressure transducer 46. An algorithm embedded upon microprocessor 134then calculates an offset value to apply to the measured value taken byfuel cell 64 to calculate a more accurate reading of the blood alcoholcontent of the gas sample. The results of this process are then used todetermine whether the vehicle's ignition system can be engaged if thevehicle is powered off. A “Pass” or “Fail” message appears on LED screendisplay 12 depending on the results of the test. If the vehicle's powersystem is already running, then the results of the test will bedisplayed on LED display screen 12, but the power to the vehicle willnot he disengaged. However, the novel interlock device of the presentinvention can sound the horn and flash the lights, if so desired, todraw attention to the rolling repeat test violator.

A dated data log is stored on microprocessor 134 in handset 10 and isused for recording a plurality of different events, including, but notlimited to, when the interlock device was powered on and powered off, ifany attempts at circumvention was attempted, results of all tests, ifthe vehicle's engine was idling for any amount of time, and if requiredtests where not performed when instructed by the interlock device (i.e.,rolling repeat tests). The information in the data log can be downloadedto a PC, a laptop, personal digital assistant (PDA) or any other kind oflike computing and digital storage device by interfacing with handset 10through a data port 136 located along a side portion of handset 10 (seeFIGS. 3, 4 and 6). In the preferred embodiment, data port 136 is a miniUSB B port. However, any type of known data port can be employed.Further, a wireless transceiver can be employed to download data fromthe data log using any known wireless transmitting technology. Inaddition to downloads, uploads can also be effected through data port136 for calibrating the interlock device, for performing maintenance,for setting preferences and for updating the software embedded onmicroprocessor 134.

As shown in FIG. 13, the interlock device of the present invention alsoincludes a base unit 138. As shown in FIG. 14, base unit 138 includes atop and bottom housing member, 140 and 142 respectively, enclosing aprinted circuit board (PCB) 144. Base unit 138 is coupled to handset 10by a detachable cable 148 which terminates on PCB 144 at connector 146.In the preferred embodiment, PCB 144 has a pair of relays 150 mountedupon a top side 166 of PCB 144. The pair of relays 150 are connected inseries with a starter mechanism (not shown) and the light and hornswitching system of a vehicle. Relays 150 react in accordance withinstructions received from microprocessor 134 which processes the gassample test (sobriety test). Relays 150 permit the starting mechanism ofa vehicle to operate if a person has passed the sobriety test andpreclude the starting mechanism if the person has failed the sobrietytest. Relays 150 are also used to sound the horn and flash the lights ofthe vehicle in response to a failed test during rolling operation of thevehicle. Additional relays could be employed within base unit 138 tooperate or preclude operation of other features of a vehicle in responseto a pass or failed test or to signal law enforcement or a supervisingagency in response to a failed test.

Although the threshold of the sobriety test is adjustable, it is set bythe manufacturer or supervising agency and can not be adjusted by theuser of the interlock device. The sobriety threshold setting is effectedby interfacing with a computing device through data port 136. In thepreferred embodiment, the sobriety threshold is set at 0.03%. Base unit138 can be mounted within the vehicle in a non-obtrusive location by aplurality of screws inserted through mounting wings 152. Top and bottomhousing members, 140 and 142 respectively, of base unit 144 include aplurality of heat dissipation vents 154 formed throughout the outerperipheral of housing members 140 and 142.

With continuing reference to FIG. 14, it is shown that PCB 144 isprovided power by cable 156 connected to a power source (not shown) ofthe vehicle in which the interlock device is mounted. A pair ofauxiliary connectors, AUX 1 and AUX 2, 158 and 160 respectively, arecoupled to PCB 144 for other interfacing uses, such as, for example,personal identification and position location features. In the preferredembodiment, AUX 1 and AUX 2 are RS-232 ports, although other datainterfacing ports can be employed. Examples of personal identificationfeatures include, but are not limited to, retina scans, voicerecognition, fingerprint verification and dental imprints. Examples ofposition location features include cellular and satellite phoneinterface, GPS (Global Positioning System), LORAN and unique beaconindicators.

Referring to FIGS. 16 and 17, it is shown how algorithmic pressurecompensation is used in the interlock device of the present invention toprovide an accurate measurement of the blood alcohol content of a personutilizing the device. As stated before, pressure transducer 46 does notcontrol the opening and closing of solenoid valve 98 as seen in theprior art inventions. In the prior art, pressure transducers have beenused to provide a constant volume of air to a fuel cell based uponfluctuating pressure by controlling the opening and closing of a valveupstream from a fuel cell. In the present invention, pressure transducer46 and solenoid valve 98 operate independently from one another toprovide a variable flow to fuel cell 64 based upon a threshold pressurebeing exceeded or not being met. An algorithmic offset is calculated inmicroprocessor 134 to provide a pressure compensated alcohol result thatis constant, without regard to pressure, as shown in FIG. 16 as a flatline. As shown in FIG. 17, a correction factor, or offset, calculated bymicroprocessor 134 through the algorithm, is used to adjust the testresult due to varying breath flow through handset 10. Pressuretransducer 46 does not effect how long solenoid valve 98 stays open orhow much breath flow is permitted to pass through to fuel cell 64.Pressure transducer 46 instead makes a measurement of the current breathflow, or pressure, and feeds that measurement to microprocessor 134 tocalculate the offset. This prohibits someone from trying to fool theinterlock device by introducing a low pressurized breath flow. Further,this novel approach to sampling the breath ensures that a high pressuredbreath flow does not saturate the fuel cell and give a false positiveresult.

In an alternate embodiment, the novel interlock device of the presentinvention can be removed from a vehicle and brought within the confinesof a residence or commercial establishment. Accordingly, the novelinterlock device of the present invention could be used as a homemonitoring device. In such alternate embodiment, handset 10 couples toan alternate power source within the residence or commercialestablishment through a power coupler. Base unit 138 can remain in thevehicle since the output relays will not be used to control a vehiclestarter or ignition system. However, signaling devices within the homemay be controlled and would therefore warrant removal of base unit 138from the vehicle to be wired to said signaling devices. Handset 10 caneasily interface with a home computer through data port 136 to downloaddata logs and upload preferences and settings and software updates andto conduct scheduled calibration and/or maintenance. An example of howthis alternate device would work in a home monitoring environment is asfollows: the offender stands in front of a web cam while the interlockdevice is connected to a home computer; software installed on the homecomputer takes a digital picture or movie of the offender taking thetest; the time is stamped on the picture or movie along with the resultsof the test; the test results are then transmitted to a host computer(supervising agency) over the Internet, by a proprietary hard-wiredconnection or by wireless transmission. The software can additionally beprogrammed to immediately notify a predetermined monitoring service oragency in the event of a failed or refused test.

Equivalent elements can be substituted for the ones set forth above suchthat they perform in the same manner in the same way for achieving thesame result.

1. A sobriety interlock device having an output coupled to a startermechanism of a motorized vehicle for detecting the presence of alcoholin a breath sample introduced into the device and for controlling thedevice output in response to a predetermined threshold level beingexceeded, the sobriety interlock device comprising: a) a handset havinga gas intake channel for receiving the breath sample, b) a breathsampling housing enclosed within the handset and having a gas samplingchannel in axial alignment with the handset gas intake channel, c) afuel cell positioned along the gas sampling channel of the breathsampling housing for measuring an alcohol vapor value of the breathsample, d) a pressure transducer located within the handset in fluidcommunication with the gas sampling channel of the breath samplinghousing for measuring a pressure value of the breath sample, e) amicroprocessor located within the handset in electrical communicationwith the fuel cell and the pressure transducer, the microprocessorcontaining an executable algorithm for determining a measured bloodalcohol content of the breath sample through an offset adjustment of themeasured alcohol vapor value in relation to the measured breath samplepressure value, the microprocessor applying a signal to the output ofthe interlock device dependent on the results of the measured bloodalcohol content as compared to the predetermined threshold level; f) asolenoid valve positioned upstream from the fuel cell along the gassampling channel of the breath sampling housing for limiting the size ofthe breath sample across the fuel cell by opening for a finite period oftime, the solenoid valve having a normally open state; and g) a powersource coupled to the handset.
 2. The sobriety interlock device of claim1, wherein the solenoid valve is electrically coupled to themicroprocessor and opens for a predetermined period of time in responseto the microprocessor receiving a signal.
 3. The sobriety interlockdevice of claim 2, wherein the predetermined period of time that thesolenoid valve opens is in the range of 100 to 700 mS, themicroprocessor sending a control signal to open and close the solenoidvalve.
 4. The sobriety interlock device of claim 1, further comprisingthe handset having a top portion and a front and back housing member,the gas intake channel of the handset disposed along the top portionthereof and having an entrance port formed through the handset fronthousing member and an exhaust port formed through the handset backhousing member.
 5. The sobriety interlock device of claim 1, furthercomprising a mouthpiece attached to an entrance port of the handset gasintake channel.
 6. The sobriety interlock device of claim 1, furthercomprising a temperature sensor disposed within the gas sampling channelof the breath sampling housing for measuring the breath sampleintroduced into the interlock device, the temperature sensorelectrically coupled to the microprocessor.
 7. The sobriety interlockdevice of claim 1, further comprising a water filter mounted within apassageway in fluid communication with the gas sampling channel of thebreath sampling housing upstream from the fuel cell, the water filtereliminating water from the breath sample while permitting alcohol vaporsto pass through to the fuel cell.
 8. The sobriety interlock device ofclaim 7, wherein the pressure value of the breath sample is measured bythe pressure transducer after the breath sample has passed into thewater filter.
 9. The sobriety interlock device of claim 8, furthercomprising a capillary tube having a proximal and distal end, thecapillary tube providing fluid communication between the breath samplinghousing and the pressure transducer, the capillary tube proximal endinserted within an aperture formed in the breath sampling housing andthe capillary tube distal end inserted within an entrance port of thepressure transducer.
 10. The sobriety interlock device of claim 1,wherein the fuel cell is a dry electrochemical fuel cell.
 11. Thesobriety interlock device of claim 1, further comprising at least oneaccelerometer for measuring movement of the motorized vehicle.
 12. Thesobriety interlock device of claim 1, further comprising a displayscreen electrically coupled to the microprocessor for displayingmessages relative to the operation and test results of the interlockdevice.
 13. The sobriety interlock device of claim 1, furthercomprising: a) a housing sensor for measuring the temperature of thebreath sampling housing, the housing sensor mounted juxtaposed an outerside wall of the breath sampling housing and electrically coupled to themicroprocessor, and b) a housing heater for increasing the temperatureof the breath sampling housing when the temperature of the housing fallsbelow a predefined tolerant level temperature, the housing heatermounted along a bottom side of the breath sampling housing andelectrically coupled to the microprocessor.
 14. The sobriety interlockdevice of claim 1, further comprising a base unit electrically coupledto the handset, the base unit including the output for the interlockdevice and having a microprocessor for interfacing with the handsetmicroprocessor and receiving the signal dependent on the results of themeasured blood alcohol content as compared to predetermined thresholdlevel.
 15. The sobriety interlock device of claim 1, wherein the outputof the interlock device comprises at least one relay.
 16. The sobrietyinterlock device of claim 1, further comprising data interfacing meansfor coupling to a computing device, the data interfacing meanselectrically coupled to the microprocessor.
 17. The sobriety interlockdevice of claim 16, further comprising a data log stored on a computingdevice readable storage medium of the handset, the data log accessiblethrough the data interfacing means.
 18. A sobriety interlock devicehaving an output coupled to a starter mechanism of a motorized vehiclehaving a power source, the interlock device measuring the blood alcoholcontent of a vehicle operator by detecting the presence of alcohol in abreath sample introduced into the device by the operator, the interlockdevice output effected in response to a predetermined threshold levelbeing exceeded, the interlock device coupled to the vehicle powersource, the sobriety interlock device comprising: a) a handset having agas intake channel for receiving the breath sample of the vehicleoperator, the gas intake channel having an entrance port and an exhaustport formed through the handset, b) a breath sampling housing enclosedwithin the handset and having a gas sampling channel in axial alignmentwith the handset gas intake channel positioned intermediate the handsetgas intake channel entrance and exhaust ports, c) a fuel cell positionedalong the gas sampling channel within the breath sampling housing formeasuring an alcohol vapor value of the breath sample of the vehicleoperator, d) a pressure transducer in fluid communication with the gassampling channel of the breath sampling housing for measuring a pressurevalue of the breath sample of the vehicle operator, the pressuretransducer having an air entrance port, e) a microprocessor coupled tothe fuel cell and the pressure transducer, the microprocessor containingan executable algorithm for determining the blood alcohol content of thevehicle operator from the breath sample introduced into the interlockdevice wherein an offset adjustment is made to the measured alcoholvapor value in response to the measured breath sample pressure value,the microprocessor applying a signal to the output of the interlockdevice dependent on the results of the measured blood alcohol content ascompared to the predetermined threshold level; f) a solenoid valvepositioned upstream from the fuel cell along the gas sampling channel ofthe breath sampling housing, the solenoid valve in a normally openstate, the solenoid valve limiting the size of the breath sample acrossthe fuel cell by remaining open f or a predetermined time, the solenoidvalve coupled to the microprocessor and changing states in response toreceipt of a control signal from the microprocessor, the solenoid valvechanging from its normally open state to a closed state when energized;and g) a base unit enclosing the interlock device output coupled to thehandset.
 19. The sobriety interlock device of claim 18, furthercomprising a temperature sensor disposed within the gas sampling channelof the breath sampling housing for measuring the breath sample of thevehicle operator introduced into the interlock device, the temperaturesensor coupled to the microprocessor.
 20. The sobriety interlock deviceof claim 18, further comprising a water filter mounted within apassageway in fluid communication with the gas sampling channel of thebreath sampling housing upstream from the fuel cell, the water filtereliminating water from the breath sample while permitting alcohol vaporsto pass through to the fuel cell.
 21. The sobriety interlock device ofclaim 18, further comprising a capillary tube having a proximal anddistal end, the capillary tube providing fluid communication between thebreath sampling housing and the pressure transducer, the capillary tubeproximal end inserted within an aperture formed in the breath samplinghousing, the capillary tube distal end inserted within the pressuretransducer air entrance port.
 22. The sobriety interlock device of claim18, further comprising at least one accelerometer for measuring movementof the motorized vehicle.
 23. The sobriety interlock device of claim 18,further comprising a display screen enclosed within the handset andcoupled to the microprocessor, the display screen displaying messagesrelative to the operation and test results of the interlock device. 24.The sobriety interlock device of claim 18, further comprising: a) atemperature housing sensor for measuring a current temperature of thebreath sampling housing, the temperature housing sensor mountedjuxtaposed along an outer side wall of the breath sampling housing, thetemperature housing sensor coupled to the microprocessor, and b) ahousing heater for increasing the temperature of the breath samplinghousing when the temperature of the housing falls below a predefinedtolerant level temperature as measured by the temperature housingsensor, the housing heater mounted along a bottom side of the breathsampling housing and coupled to the microprocessor.
 25. The sobrietyinterlock device of claim 18, further comprising: a) data interfacingmeans for coupling to a computing device, the data interfacing meanscoupled to the microprocessor, and b) a data log stored on a computingdevice readable storage medium of the handset, the data log accessiblethrough the data interfacing means.
 26. The sobriety interlock device ofclaim 18, wherein the microprocessor is enclosed within the handsetalong a printed circuit board and communicates with the base unit by ahigh speed serial data interface.
 27. The sobriety interlock device ofclaim 18, further comprising the breath sampling housing having acut-away portion formed along a front side thereof, the cut-away portionseating and retaining the fuel cell within the breath sampling housing.28. A vehicle sobriety interlock device for measuring the blood alcoholcontent of a vehicle operator by detecting the presence of alcohol in abreath sample introduced into the device by the operator, the interlockdevice mounted within close proximity of a driver's seat of a vehicle,the interlock device comprising: a) a handset having a gas intakechannel for receiving the breath sample of the vehicle operator, the gasintake channel having an entrance port and an exhaust port formedthrough the handset, b) a breath sampling housing enclosed within thehandset and having a gas sampling channel in axial alignment with thehandset gas intake channel positioned intermediate the handset gasintake channel entrance and exhaust ports, c) an electrochemical fuelcell positioned along the gas sampling channel within the breathsampling housing for measuring an alcohol vapor value of the breathsample of the vehicle operator, d) a pressure transducer connected alongthe gas sampling channel of the breath sampling housing by a capillarytube, the pressure transducer measuring a pressure value of the breathsample of the vehicle operator, e) a solenoid valve positioned upstreamfrom the fuel cell in fluid communication with the gas sampling channelof the breath sampling housing, the solenoid valve limiting the size ofthe breath sample across the fuel cell by remaining open for apredetermined amount of time, the solenoid valve held in a normally openstate, f) a microprocessor coupled to the fuel cell, the pressuretransducer and solenoid valve, the microprocessor containing anexecutable algorithm for determining the blood alcohol content of thevehicle operator from the breath sample introduced into the interlockdevice wherein an offset adjustment is made to the measured alcoholvapor value in response to the measured breath sample pressure value,the microprocessor enclosed within the handset, g) a base unit enclosingan output of the interlock device, the base unit communicating with themicroprocessor within the handset, the output precluding a startermechanism of the vehicle from engaging if a signal received from thehandset microprocessor has determined that the blood alcohol content ofthe breath sample of the vehicle operator exceeds a predeterminedthreshold level; and h) a power source coupled to the handset and thebase unit.
 29. The sobriety interlock device of claim 28, furthercomprising a breath temperature sensor mounted within the gas samplingchannel through a bore formed in the breath sampling housing, the breathtemperature sensor measuring the breath sample of the vehicle operatorintroduced into the interlock device, the temperature sensor coupled tothe microprocessor within the handset.
 30. The sobriety interlock deviceof claim 28, further comprising a water filter mounted within apassageway in fluid communication with the gas sampling channel of thebreath sampling housing upstream from the fuel cell and the solenoidvalve such that the solenoid valve is positioned intermediate the waterfilter and the fuel cell, the water filter eliminating water from thebreath sample while permitting alcohol vapors to pass thereby.
 31. Thesobriety interlock device of claim 28, further comprising at a pair ofaccelerometers for measuring movement of the motorized vehicle along anX and Y axis, respectively.
 32. The sobriety interlock device of claim28, further comprising a display screen mounted upon the handset andcoupled to the microprocessor, the display screen displaying messagesrelative to the operation and test results of the interlock device. 33.The sobriety interlock device of claim 28, further comprising: a) thebreath sampling housing including a body portion in which the gassampling channel is formed, the body portion having first and secondopposed outer side walls, b) the solenoid valve mounted along the firstouter side wall of the body portion, c) an air entrance channel and anair exhaust channel formed through the body portion first outer sidewall in fluid communication with solenoid valve, d) the air entrancechannel positioned between the water filter and the solenoid valve, e)the air exhaust channel positioned between the solenoid valve and anentrance port of the fuel cell, and f) the fuel cell including anexhaust port for expelling any unused breath sample introduced into thehandset.
 34. The sobriety interlock device of claim 28, furthercomprising: a) a temperature housing sensor for measuring a currenttemperature of the breath sampling housing, the temperature housingsensor mounted juxtaposed along an outer side wall of the breathsampling housing, the temperature housing sensor coupled to themicroprocessor within the handset, and b) a housing heater forincreasing the temperature of the breath sampling housing when thetemperature of the housing falls below a predefined tolerant leveltemperature as measured by the temperature housing sensor, the housingheater mounted along a bottom side of the breath sampling housing andcoupled to the microprocessor.
 35. The sobriety interlock device ofclaim 28, further comprising: a) data interfacing means for coupling toa computing device, the data interfacing means coupled to themicroprocessor within the handset, and b) a data log stored on acomputing device readable storage medium of the handset, the data logaccessible through the data interfacing means.
 36. The sobrietyinterlock device of claim 28, further comprising at least one auxiliaryport disposed within the handset and coupled to the microprocessor. 37.The sobriety interlock device of claim 28, further comprising a speakercoupled to the microprocessor for providing audio signaling relative tooperation of the interlock device.
 38. A sobriety interlock devicecoupled to a starter mechanism of a vehicle and having an output coupledto a computing device, the sobriety interlock device detecting thepresence of alcohol in a breath sample introduced into the device andfor controlling the device output in response to a predeterminedthreshold level being exceeded, the sobriety interlock devicecomprising: a) a handset having a gas intake channel for receiving thebreath sample, b) a breath sampling housing enclosed within the handsetand having a gas sampling channel in axial alignment with the handsetgas intake channel, c) a fuel cell positioned along the gas samplingchannel of the breath sampling housing for measuring an alcohol vaporvalue of the breath sample, d) a pressure transducer located within thehandset in fluid communication with the gas sampling channel of thebreath sampling housing for measuring a pressure value of the breathsample, e) a microprocessor located within the handset in electricalcommunication with the fuel cell and the pressure transducer, themicroprocessor containing an executable algorithm for determining ameasured blood alcohol content of the breath sample through an offsetadjustment of the measured alcohol vapor value in relation to themeasured breath sample pressure value, the microprocessor applying asignal to the output of the interlock device dependent on the results ofthe measured blood alcohol content as compared to the predeterminedthreshold level; f) a solenoid valve held in a normally open state, andg) a power source coupled to the handset.